While today's students and adults are keeping up intellectually with previous generations of Americans they are mostly falling behind fast-advancing foreigners, The New York Times noted in an editorial.

The OECD report looked at people ages 16 to 65 in 24 developed countries focusing on the ability to understand written material, use mathematical concepts, and interpret data using computers. It found that Americans were comparatively weak in literacy, close to the bottom in numeracy, and slightly below average in using computers for problem solving.

In literacy, for example, 12 percent of US adults scored at the highest levels, just about average for the developed world. One in six scored below average compared with one in 20 in Japan.

Other key findings:

African-Americans and Hispanics are overrepresented in the low-skilled population.

Literacy skills are associated with employment and socio economic prospects.

Adults born to better-educated parents tend to have stronger literacy skills.

The Times said the report shows more needs to be done for education, noting countries at the forefront of the digital revolution such as Finland "broadened access to education, improved teacher training and took other steps."

"In every subject, from math and science to reading and social studies, homeschooled kids out-perform public school kids by 30 percentage points or more. Studies confirm they're resilient and focused, doing well regardless of household income or whether their parents were certified teachers or [whether] a large sum of money was spent on their education."

There is still a stigma attached to homeschooling and it is unfeasible for all parents, said Russell, who called the OECD findings "disheartening — staggering even — though unsurprising."

But she said homeschooled students outperform their public school cohorts in communication, maturity, socialization and daily living.